5. Intermedier metabolism of kidney and red blood cell Flashcards
2 Glucose transporters on the kidney
SGLT2:
Low affinity
High transport capacity
SGLT1:
High affinity
Low transport capacity
Comparison of SGLT1 and SGLT2: Na+–Glucose (Galactose) Symport
-> Characteristics of SGLT1
Comparison of SGLT1 and SGLT2: Na+–Glucose (Galactose) Symport
-> Characteristics of SGLT2
The treatment of cholera and other dehydrating diarrheal diseases was revolutionized by the promotion of____ (which drug?)
oral rehydration solution (ORS)
The treatment of cholera and other dehydrating diarrheal diseases was revolutionized by the promotion of oral rehydration solution (ORS)
-> Why is it efficient?
the efficacy of which depends on the fact that glucose-facilitated
absorption of sodium and water in the small intestine remains
intact in the presence of cholera toxin.
What happen in liver during Short term fasting (glucagon effect)?
gluconeogenesis start
What happen in kidney during Short term fasting (glucagon effect)?
no gluconeogenesis
What happen in liver during Long term fasting (adrenaline, corticosteroids)?
intensive gluconeogenesis
What happen in kidney during Long term fasting (adrenaline, corticosteroids)?
intensive gluconeogenesis
What happen in liver if there is a High level of ketone bodies (metabolic acidosis)?
reduced gluconeogenesis
What happen in kidney if there is a High level of ketone bodies (metabolic acidosis)?
intensive gluconeogenesis
What are the 2 Most important precursors in liver?
lactate, alanine
What are the 2 Most important precursors in KIDNEY?
lactate, glutamine
How does Ammonia transport in the form of glutamine?
Glutamine synthetase localized in ___
the pericentral zone
Glutamine synthetase localized in the pericentral zone
-> What happen in periportal zone?
Ammonia uptake Ammonia release
Urea production
by ornithine/urea cycle
What happen in pericentral zone?
Detoxification of ammonia by glutamine synthetase
What is Pathway of renal glutamine catabolism during chronic acidosis.?
What is the Role of glutamin in proliferating cells?
The rates of utilization of both glucose and glutamine are high in rapidly dividing cells (enterocytes, lymphocytes, tumor cells)
Role of glutamin in proliferating cells
-> Glutaminolysis in proliferating cells?
Role of glutamin in proliferating cells
-> The biosynthetic origins of purine ring atoms
Role of glutamin in proliferating cells
-> The biosynthetic origins of pyrimidine ring atoms
What is the role of Kidney lipid metabolism?
energy sources of the cortex, the sources of fatty acid
Which organ plays
a major role in carnitine metabolism (excretion, reabsorption)?
Kidney
Intermedier metabolism of erythrocytes
-> What is the glucose entry?
Transporters in erythrocytes:
- Glut1 transporter (Harper 30th ed. p691)
- sodium-potassium ATPase (Harper 30th ed. p490-491)
Intermedier metabolism of erythrocytes
-> Characteristics of Passive transport in?
- high rates of diffusion down a concentration gradient
- saturability
- stereospecificity
How does Red blood cell metabolism occur?
Via anaerobic glycolysis and shunts
How does pentose phosphate pathway occur in red blood cell metabolism?
What is the Role of NADPH and glutathione?
protecting cells against highly reactive oxygen derivatives
What is the Role of NADPH and glutathione?
protecting cells against highly reactive oxygen derivatives
What are 3 nucleotide salvage reactions?
Where does ribose-5-phosphate come from?
Pentose phosphate pathway
What is methemoglobinemia?
a blood disorder in which an abnormal amount of methemoglobin is produced
What is Acquired methemoglobinemia?
exposure to oxidizing substances or drugs, including nitrates, free radicals
What is Congenital methemoglobinemia?
congenital deficiency of the NADH- dependent cytochrome b5 reductase (methemoglobin reductase)
(rare)
The 2,3-Bisphosphoglycerate pathway in erythrocytes
The 2,3-Bisphosphoglycerate pathway in erythrocytes
What is the Effect of 2,3-bisphosphoglycerate on oxygen binding to hemoglobin
An increase in BPG concentration, decreases the affinity of hemoglobin for O2
How does blood transfusion occur?
The 2,3-diphosphoglycerate (2,3-BPG) levels decline rapidly over the first week of blood storage, falling to undetectable levels by the end of week 2.
Because of the loss of 2,3-BPG, stored RBC release O2 to the tissues less readily than normal cells.
After transfusion, however, 2,3-BPG is rapidly resynthesised (hours, days to 95%)